Quantitative ultrasound of the hand phalanges in a cohort of monozygotic twins: influence of genetic and environmental factors

2005 ◽  
Vol 34 (11) ◽  
pp. 727-735 ◽  
Author(s):  
G. Guglielmi ◽  
F. de Terlizzi ◽  
I. Torrente ◽  
R. Mingarelli ◽  
B. Dallapiccola
Keyword(s):  
Environmental Factors ◽  
Quantitative Ultrasound ◽  
Monozygotic Twins ◽  
Hand Phalanges ◽  
Genetic And Environmental Factors

scholarly journals Genetic and environmental factors in the determination of general cognitive abilities: a twin study

2020 ◽  
Vol 15 (2) ◽  
pp. 171-176
Author(s):  
Annu ◽  
Bimla Dhanda
Keyword(s):  
Environmental Factors ◽  
Cognitive Abilities ◽  
Twin Study ◽  
Monozygotic Twins ◽  
Heritability Estimate ◽  
Intelligence Scale ◽  
Wide Range ◽  
Heritability Estimates ◽  
Genetic And Environmental Factors

The present investigation of twin study elucidated the contribution of genetic and environment to a wide range of general cognitive abilities. To conduct twin study 100 pairs of twins from two districts, namely: Bhiwani (n = 90) and Hisar (n = 110) of Haryana State, genetic and environmental influences were assessed in twin study design. The cognitive abilities of twins were measured using the Wechsler Intelligence Scale for Children (WISC-R). Home Observation for Measurement of the Environment (HOME) Inventory was taken to examine the home environment of twins. Heritability estimate was used to analyze the genes contributing to shape the cognitive abilities of twins. The result of heritability estimates revealed that the heritability estimates of general cognitive abilities namely: information (62%), similarities (57%), vocabulary (60%) and comprehension (55%) in Bhiwani district and in Hisar district, the heritability estimates were 58 per cent, 55 per cent, 56 per cent and 51 per cent for information, similarities, vocabulary and comprehension general cognitive abilities, respectively. The findings clearly elucidated that the general cognitive abilities were more influenced by genetic background than the environmental factors. The paternal involvement and physical environment were strongly associated with general cognitive abilities of twins. The monozygotic twins were more correlated in their general cognitive abilities than the dizygotic twins.

A Male Monozygotic Twinship Discordant for Homosexuality

1971 ◽  
Vol 118 (547) ◽  
pp. 675-682 ◽  
Author(s):  
K. Davison ◽  
H. Brierley ◽  
C. Smith
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Prison Population ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
The Third ◽  
Relative Contribution ◽  
Quantitative Rating ◽  
Genetic And Environmental Factors ◽  
Sexual Identification

The relative contribution of genetic and environmental factors to the development of homosexual behaviour is a controversial subject. The original suggestion that homosexuality is a purely inherited trait has been attributed to Krafft-Ebing (Kallmann, 1952). Perhaps the strongest support for this view was Kallmann's series of 40 male monozygotic twin pairs showing 100 per cent concordance for the overt practice and quantitative rating of homosexual behaviour (Kallmann, 1952). This report has been criticized, and Kallmann later conceded that the 100 per cent concordance was possibly a statistical artefact (Kallmann, 1960). Habel (1950), who obtained the index twins from a prison population, found concordant homosexuality in 3 out of 5 monozygotic pairs (60 per cent), but none of 5 dizygotic pairs. In a more recent study, Heston and Shields (1968) found concordant homosexuality in 2 out of 5 monozygotic pairs (40 per cent) and 1 out of 7 dizygotic pairs (14 per cent). Heston and Shields (1968) also report a family with a sibship of 14 which included 3 pairs of male monozygotic twins, in two of which both twins were homosexual and in the third both heterosexual; no environmental factors which differentiated the homosexual from the heterosexual sibs could be detected. These workers also refute the suggestion that the tendency for monozygotic twins to be more alike with regard to homosexuality than dizygotic twins is related not to genetic factors but to problems of sexual identification which predispose to homosexuality (Money, 1962) by pointing out that there is no evidence that monozygotic twins per se are especially prone to become homosexual.

Genetic and Environmental Factors in Monozygotic Twins with Crohn’s Disease and Their First-Degree Relatives: A Case Report

Digestion ◽  
2005 ◽  
Vol 71 (4) ◽  
pp. 262-265 ◽  
Author(s):  
Ida Vind ◽  
Cathrine Jespersgaard ◽  
Lotte Hougs ◽  
Lene Riis ◽  
Lotte Dinesen ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Case Report ◽  
Crohn's Disease ◽  
Environmental Factors ◽  
Monozygotic Twins ◽  
First Degree Relatives ◽  
Genetic And Environmental Factors

Heritability of Initiation and Duration of Breastfeeding Behavior

2013 ◽  
Vol 16 (2) ◽  
pp. 575-580 ◽  
Author(s):  
Lucia Colodro-Conde ◽  
Juan F. Sánchez-Romera ◽  
Juan R. Ordoñana
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Model Fitting ◽  
Monozygotic Twins ◽  
Best Fitting ◽  
Short And Long Term ◽  
Genetic And Environmental Factors ◽  
Duration Of Breastfeeding ◽  
Natural Way

Breastfeeding is considered the best and most natural way of feeding infants during the first months of life. Breastfeeding has multiple short- and long-term benefits for the health of the mother and babies, and from an evolutionist standpoint, it would be a behavior worth preserving throughout time. The aim of the present study was to explore the relative influence of genetic and environmental factors in this behavior. Three hundred and ninety pairs of adult female twins provided information about whether they breastfed their children and for how long. Three variables were analyzed: initiation and duration for the first baby, and mean duration for the complete offspring. Polychoric correlations were consistently higher for monozygotic twins, supporting a role for genetic factors (0.49 vs. 0.22 for initiation; 0.44 vs. 0.22 for duration in the first newborn; and 0.52 vs. 0.31 for duration on average). Model-fitting analyses found that in the best-fitting model, variance was explained by additive genetic and non-shared environmental factors, with estimated heritabilities ranging from 0.39 to 0.52 in the measures studied. The rest of the variance would be due to unique environmental factors. We conclude that genetic factors have a significant impact on the complex behavior of breastfeeding.

Psychoses in the Offspring of Schizophrenic Monozygotic Twins and their Normal Co-Twins

1971 ◽  
Vol 118 (542) ◽  
pp. 43-52 ◽  
Author(s):  
Margit Fischer
Keyword(s):  
Mental Illness ◽  
Environmental Factors ◽  
Monozygotic Twins ◽  
Genetic And Environmental Factors

The difficulty of examining separately the genetic and environmental factors responsible for mental illness has resulted in different approaches to surmount this obstacle.

Coarctation of the aorta in dizygotic twins

2000 ◽  
Vol 10 (1) ◽  
pp. 46-48 ◽  
Author(s):  
Monica Caldas ◽  
Rami Dhillon
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Environmental Factors ◽  
Congenital Heart ◽  
Monozygotic Twins ◽  
Coarctation Of The Aorta ◽  
In Vitro Fertilisation ◽  
Dizygotic Twins ◽  
Genetic And Environmental Factors

AbstractThe incidence of congenital heart disease is higher in monozygotic than dizygotic twins, with a higher concordance rate. Although coarctation of the aorta has previously been reported in monozygotic twins, to the best of our knowledge it has not been described in dizygotic twins. We report here such a concurrence in dizygotic twins conceived by in-vitro fertilisation. The finding provides support for both genetic and environmental factors in the aetiology of congenital heart disease. Furthermore, it highlights our lack of data regarding the outcome of in-vitro fertilisation.

scholarly journals Environmental Agents Involved in the Cause of Primary Biliary Cirrhosis

2010 ◽  
Vol 29 (6) ◽  
pp. 329-336 ◽  
Author(s):  
Elias Kouroumalis
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Environmental Factors ◽  
Monozygotic Twins ◽  
Cholestatic Liver Disease ◽  
Biliary Cirrhosis ◽  
Infectious Agents ◽  
Immune Mediated ◽  
Environmental Agents ◽  
Autoimmune Conditions ◽  
Genetic And Environmental Factors

Primary biliary cirrhosis (PBC) is an immune mediated chronic cholestatic liver disease with a slowly progressive course It is a universal disease with a reported latitudinal gradient in prevalence and incidence. The aetiology of primary biliary cirrhosis is still unknown. It is characterized by a 60% concordance in monozygotic twins and is considered an autoimmune disease because of several features common to other autoimmune conditions and the relatively homogeneous serological and biochemical features. However geoepidemiological and clinical studies strongly imply that environmental factors also play an important role. It is accepted that the disease is clearly the result of a combination of genetic and environmental factors. Several risk factors have been suggested to be associated with PBC, including exposure to infectious agents and chemical xenobiotics. This review will attempt to place such factors in perspective.

scholarly journals Growth and Development of Dentofacial Complex influenced by Genetic and Environmental Factors using Monozygotic Twins

2017 ◽  
Vol 18 (9) ◽  
pp. 754-758 ◽  
Author(s):  
KK Manjusha ◽  
K Jyothindrakumar ◽  
A Nishad ◽  
K Madhav Manoj
Keyword(s):  
Environmental Factors ◽  
Correlation Coefficient ◽  
Growth And Development ◽  
Dominant Role ◽  
Monozygotic Twins ◽  
Twin Studies ◽  
The Body ◽  
Gonial Angle ◽  
Lateral Cephalograms ◽  
Genetic And Environmental Factors

ABSTRACT Aim The purpose of this study was to determine the possible effects of genetic and environmental factors on dentofacial complex using monozygotic twins. Materials and methods The study sample was made of 21 pairs of monozygotic twins (14 female pairs and seven male pairs) between 10 and 25 years. Pretreatment lateral cephalograms were used which were traced and digitized, and various landmarks to determine the anteroposterior and vertical proportions were marked. Samples were divided into two groups. The correlation between groups was found by calculating Pearson's product moment correlation coefficients. Results The range of the correlation coefficient was from 0.705 to 0.952. Gonial angle showed the highest correlation coefficient (0.952), while saddle angle showed the lowest correlation coefficient (0.705). Conclusion The growth and development of craniofacial complex is under mutifactorial control. However, genetic influences do tend to play a dominant role. Clinical significance By studying identical twins, we can study about the interaction of the environment with the genes and how it affects the growth and development of the body in general and dentofacial complex in particular. By utilizing twin studies, we can identify whether a particular trait, disease, or disorder is influenced more strongly by genetics or by the environment. Success of orthodontic treatment depends on a proper diagnosis of the problem including its etiological factors. Genetic studies let the orthodontists to understand the effects of genetic and environmental factors in the growth and development of dentofacial complex better and allows to prevent or treat malocclusions and skeletal anomalies in better ways. How to cite this article Manjusha KK, Jyothindrakumar K, Nishad A, Manoj KM. Growth and Development of Dentofacial Complex influenced by Genetic and Environmental Factors using Monozygotic Twins. J Contemp Dent Pract 2017;18(9):754-758.

Quantitative ultrasound at the hand phalanges in monozygotic twins: a preliminary report

2002 ◽  
Vol 28 (9) ◽  
pp. 1153-1156 ◽  
Author(s):  
Bogna Drozdzowska ◽  
Wojciech Pluskiewicz ◽  
Francesca de Terlizzi
Keyword(s):  
Quantitative Ultrasound ◽  
Preliminary Report ◽  
Monozygotic Twins ◽  
Hand Phalanges

scholarly journals A Comparison of Personality, Life Events, Comorbidity, and Health in Monozygotic Twins Discordant for Anorexia Nervosa

2017 ◽  
Vol 20 (4) ◽  
pp. 310-318 ◽  
Author(s):  
Laura M. Thornton ◽  
Sara E. Trace ◽  
Kimberly A. Brownley ◽  
Monica Ålgars ◽  
Suzanne E. Mazzeo ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Environmental Factors ◽  
Life Events ◽  
Statistical Power ◽  
Monozygotic Twins ◽  
Health And Wellbeing ◽  
Gastrointestinal Problems ◽  
Genetic And Environmental Factors ◽  
The Impact ◽  
Mz Twins

Genetic and environmental factors contribute to the etiology of anorexia nervosa (AN). The co-twin control design is one of the most powerful methods available to evaluate environmental factors that could contribute to differences between monozygotic (MZ) twins who are discordant for AN. Using available data from a unique and rare sample of 22 Swedish female MZ pairs discordant for AN, we compared personality, life events, comorbidity, and health factors. Twins with AN had significantly higher perfectionism scores than unaffected co-twins and reported younger ages at first diet than unaffected co-twins who had dieted. Consistent with previous literature, more twins with AN reported gastrointestinal problems than unaffected co-twins. Although not significant due to low statistical power, more unaffected co-twins reported experiencing emotional neglect than twins with AN. Early dieting may be a harbinger of the development of AN or an early symptom. Higher perfectionism may represent a risk factor, sequela, or both. Sibling perception of neglect is noteworthy given the impact of an ill child with AN on family function and wellbeing. The health and wellbeing of siblings should be addressed clinically when one child in the family suffers from AN.

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